C 6 1 



II. 



HOW TO INTBODUCE OEDEE INTO THE RELATIONS 



BETWEEN BEITISH WEIGHTS AND MEASUEES. By 



G. JOHNSTONE STONEY, M.A., So.D., F.E.S. 



(Platk I.) 



[Read February 17 ; Received for Publication, February 17 ; 



Published May 2, 1903.] 



The weights and measures that may lawfully be used in the 

 United Kingdom are : — 



1. The Imperial system of weights and measures, for all 



commodities. 



2. Metric weights and measures, for all commodities. 



3. Apothecaries' weights and measures, for drugs when sold by 



retail. 



4. The ounce Troy and its decimal subdivisions, for bullion 



and precious stones. 



5. Coin weights, for coins. 



This is a complete list of British weights and measures, as the 

 law at present stands. 



In the time of Edward II., the British inch was denned as the 

 length of three barley-corns, round and dry, taken from the 

 middle of the ear, and placed end to end. The foot and yard 

 were derived from the inch as determined in this way. In the 

 time of Henry VII. a standard yard was made, and the foot and 

 inch were derived from it. This was an immense improvement 

 upon the earlier practice. Another yard, supposed to be a copy 

 of Henry YII.'s standard, took its place as the English standard 

 yard in the time of Queen Elizabeth. In 1742 a brass yard was 

 constructed by Graham for the Royal Society, which was derived 

 from the yard-measure of Queen Elizabeth; and a copy of 

 Graham's yard was made by Bird, the optician, in 1760, which 

 Parliament adopted as the British standard yard. It continued 

 the standard until 1834. Our present standard was made in 



